Detection of Cells Producing Antibody to Hepatitis B Surface Antigen by an Indirect Hemolytic Plaque Assay

Hemolytic plaque assays in gel were performed against burro red blood cells (BRBC) conjugated with hepatitis B surface antigen (HBS Ag). On indirect assay, spleen cells from HBS Ag-immunized mice gave 27–68 times more plaques than cells from unimmunized mice. No difference in numbers of plaques was seen between immunized and unimmunized mice when tested against either plain or control-conjugated BRBC. Hemolytic plaque assays can be used to study cells producing antibody to HBS Ag and should help to delineate aspects of the immune response to this viral antigen in chimpanzees and man during acute viral hepatitis, type B, and in the chronic HBS Ag carrier state.